Physicists say they may have detected the first direct evidence of dark matter through an unexplained particle interaction recorded by the LUX-ZEPLIN experiment. The signal, a single suspected collision between an ordinary particle and what researchers call a Weakly Interacting Massive Particle or WIMP, came from a detector containing 10 tons of ultrapure liquid xenon buried one mile underground at the Sanford Underground Research Facility in South Dakota.
Dark matter makes up roughly 85 percent of the mass in the universe, yet scientists cannot directly observe it because it does not interact with light or electromagnetic radiation. This has made identifying what dark matter actually is one of physics' most persistent puzzles.
The detected event remains inconclusive. There is a 0.5 percent chance the signal could be explained by known background interactions rather than dark matter, meaning the finding is not statistically significant enough to confirm a WIMP detection. Sam Eriksen, team leader from the University of Bristol, said in a statement that the interaction was important precisely because the researchers understood their detector well enough to recognize an anomaly.
If confirmed as a WIMP interaction, the signal suggests these hypothetical particles have a mass about 200 times greater than a proton and would interact with ordinary matter in ways not predicted by the simplest models. As the LUX-ZEPLIN experiment continues gathering data, researchers expect only a handful of additional detections would be needed to confirm the existence of WIMP dark matter.
The team presented its findings at the 2026 TeV Particle Astrophysics conference and has submitted the results to the journal Physical Review Letters.